surface-bridge

An Axum HTTP server on 127.0.0.1:7890 providing Tier 2 UI rendering for learn-domain skills: /health, /mcp/detect-surface-tier, /mcp/render-ui-intent, and /mcp/collect-response.

Skills never render UI directly — they emit a UiIntent and the bridge resolves the harness's capability tier. Installed as a macOS launchd service by install-skills-flat.sh.